A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A huge musical instrument played by the ocean.

Once the gateway to the utopian dream-village of a Civil War embalmer.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

A strange house built only at night, with rumored mystic inspiration.

Ghost town with a beer-drinking goat for mayor.

A church dedicated to the Mexican skeleton saint.

The only castle in North America to ever house European sovereigns.

Superstitious? Discover the witchy side of Mexico through its largest esoteric market.

Frida Kahlo's childhood home, now a museum of her life and works.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

An ancient capital city that dates back 3,000 years and harbors many surprises.

Charnel house at the foot of Mount Sinai.

Mysterious lost empire of the Silk Road.

Ruins of the Crusaders' headquarters.

Only a handful of these gorgeous historic waterwheels remain but even those are in danger from local unrest.

Yemen's "Stone Palace" looks like it was carved right out of the tall stone column on which it is built.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A marvel of Byzantine engineering under the streets of Istanbul.

The most visited, and possibly most controversial, museum in Germany.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

The Magical World of George Phar Legler.

Miniature art that tells an enormous story.